Occlusion in Complete Denture

ByBy Bhushan Chavan Bhushan Chavan

Occlusion in Complete Denture

Introduction

What is Occlusion? Occlusion is a relationship between the occlusal surfaces of maxillary and mandibular teeth when they are in contact.

Ideal Requirements Of Complete Denture Occlusion

- Stability of denture and occlusion in centric and eccentric relation

- Balanced occlusal contact in all eccentric movements.

- Reduced cuspal height to control horizontal forces.

- Functional lever balance sholud be obtained by vertical tooth to ridge crest relationship

- Cutting,penetrating and shearing efficiency of the occlusal surface

- Incisal clearance during posterior functions like chewing

- Minimal area of contact to reduce pressure while crushing food

Units In Complete Denture Occlusion INCISAL UNITINCISAL UNIT : Includes four incisors

WORKING UNITWORKING UNIT : Includes Canine and Posterior teeth of the sides toward which mandible moves

BALANCING UNITBALANCING UNIT : Includes canine and posterior teeth opposite to the working side.

Ideal Requirements Of Occlusal Units

INCISAL UNITINCISAL UNIT 1)Sharp incisal edges 2)No contact during mastication 3)Shallow incisal guidance 4)Increased horizontal overlap WORKING UNITWORKING UNIT 1)Cusp for grinding and cutting efficiency 2)Smaller buccolinual width 3)Plane of occlusion parallel to the plane of ridge 4)Occlusal load directed to the anteroposterior centre of denture BALANCING UNITBALANCING UNIT 1)Second molar Should be in contact during protrusive action 2)They should have contact along with the working side at the

end of chewing cycle 3)Smooth guiding contacts for lateral and protrusive movements

CONCEPTS OF OCCLUSIONBALANCED OCCLUSION

NON-BALANCED OCCLUSION

LINGUALIZED OCCLUSION

BALANCED OCCLUSIONDEFINITION:- The simultaneous contacting of the

maxillary and mandibular teeth on the right and left and in the posterior and anterior occlusal areas in centric and eccentric positions, developed to lessen or limit tipping or rotating of the denture bases in relation to the supporting structures.

It is associated cusp form posterior teeth

BALANCED OCCLUSION(contd.)

REQUIREMENTS:-All the teeth of working side should glide evenly

against opposing teeth No single tooth should produce any interference or

any disocclusionThere should be contacts in balancing side but they

should not interfere with smooth gliding movements of working side

There should be simultaneous contact during protrusion

BALANCED OCCLUSION(contd.)

GENERAL CONSIDERATIONS:-Ideal balance can be achieved in cases with wide

and large ridges and in complete dentures with teeth arranged close to the ridge

Complete dentures that have teeth arranged away from the ridge and those that rest on narrow and short ridges will have poor balanced occlusion

Teeth that have narrow buccolingual width provide ideal balanced occlusion

Ideal balance can be achieved by arranging the teeth slightly on lingual side of ridge

BALANCED OCCLUSION(contd.)TYPES:-

- UNILATERAL BALNCED OCCLUSION

- BILATERAL BALANCED OCCLUSION

- PROTRUSIVE BALANCED OCCLUSION

- LATERAL BALANCED OCCLUSION

BALANCED OCCLUSION(contd.)UNILATERAL BALANCED OCCLUSIONUNILATERAL BALANCED OCCLUSIONOcclusal surfaces of teeth on one side when

they occlude simultaneously with smooth uninterrupted glide

Related to FPD

BILATERAL BALANCED OCCLUSIONBILATERAL BALANCED OCCLUSIONSimultaneous contact occurs on both sides in

centric and eccentric relations

BALANCED OCCLUSION(contd.)PROTRUSIVE BALANCED OCCLUSIONPROTRUSIVE BALANCED OCCLUSIONWhen mandible moves in forward direction

and the occlusal contacts are smooth and simultaneous anteriorly and posteriorly.

LATERAL BALANCED OCCLUSIONLATERAL BALANCED OCCLUSIONMinimal simultaneous three point contact

present during lateral movement of mandible

BALANCED OCCLUSION(contd.)

FACTORS INFLUENCING BALANCED OCCLUSIONInclination of condylar path or condylar guidance

Incisal guidance

Orientation of plane of occlusion or occlusal plane

Cuspal angulation

Compensating curves

NON-BALANCED OCCLUSIONDEFINITION:-It is an arrangement of teeth with form or

purpose It is used to set non-anatomic teeth in

occlusionIt includes following conceptsSpherical theoryOrganic or Organised occlusionOcclusal balancing ramps for protrusive

balanceTransographics

NON-BALANCED OCCLUSION (contd.)Spherical theorySpherical theory According to this theory,anteroposterior and mesiodistal inclines

of artificial teeth should be arranged in harmony with spherical surface.

Organic occlusionOrganic occlusion Arrangement of teeth should relate the occlusal elements of

teeth so that teeth will be in harmony with muscles and joints in function

It has 3 phases of mutually interdependent protecttion - Posterior teeth should protect anterior teeth in centric occlusal

position - The maxillary incisors should have vertical overlap sufficient to

provide the separation of the posterior teeth when incisors are in end to end contact

- In lateral mandibular positions outside the masticatory cyclic movements the cuspid should prevent the contact of all other teeth

NON-BALANCED OCCLUSION (contd.)

General considerations:-Opposing teeth should not contact when

jaws are in eccentric relation since it may give destabilizing forces to the basal seat area

Tooth contact should occur only when the mandible is in centric relation to maxilla

The patient should be encouraged to repeat mandibular movements till there is no discomfort in centric relation

LINGUALIZED OCCLUSIONIt involves the use of large palatal cusps

against wide lower central fossa

Maxillary palatal cusps are main functional occlusal elements

Characteristics BALANCED NON-BALANCED LINGUALIZED

OCCLUSION OCCLUSION OCCLUSION

1.Better + - +

Esthetics

2.Ease of + - +

penetration

3.Denture

stability during + - +

parafunctional

movements

4.Simple techinique - + +

Characteristics BALANCED NON-BALANCED LINGUALIZED

OCCLUSION OCCLUSION OCCLUSION

5.Decreased lateral - + +

forces

6.Ease of adjustment - + +

7.Class II and III - + +

jaw relations

8.Good stability, - + +

forces centralized

& neutralized